Chad Varah was one of those people inspired by a sudden brainwave from which developed an international organisation of almost breathtaking simplicity. In 1953 he read that in Greater London three people killed themselves every day, and it occurred to him that what people who were feeling suicidal or in despair most needed was an emergency telephone line akin to 999. This he set up in the crypt of St Stephen Walbrook, a magnificent Wren church in the City of London, and so were born the Samaritans.

During the greatest period of expansion, from about 1964 until 1973, on average a new Samaritan branch was established in the United Kingdom every eight weeks. Today there are about 200 centres throughout the British Isles, manned 24 hours a day, and the work of the Samaritans is conducted in around 40 countries overseas.

Edward Chad Varah was born in 1911, at Barton-upon-Humber. He was the eldest of nine children and his father was parish priest of a church in Lincolnshire founded by the seventh-century converter of the Midlands, St Chad, after whom Edward was baptised. The name Varah is almost certainly Ukrainian in origin, but the family had lived in Yorkshire since at least 1537. Chad Varah was educated at Worksop College in Nottingham, and gained an Exhibition in Natural Sciences to Keble College, Oxford.

From there he went on to study for the ministry at Lincoln Theological College, where one of his teachers was the sub-warden Michael Ramsey, who later became Archbishop of Canterbury. He was ordained deacon in 1935 and priest a year later, and after serving three assistant curacies, Varah was inducted, in 1942, to his first living, Holy Trinity, Blackburn, where he remained until 1949. For the next four years he was vicar of the Church of St Paul, Clapham Junction, and it was in 1953, the year he founded the Samaritans, that he was offered St Stephen Walbrook by the Worshipful Company of Grocers. He was also working at the time as a children's comic scriptwriter for Eagle, Robin and Swift, and was one of the creators of the cartoon space hero Dan Dare.

In talking about the reason he set up an emergency telephone service for people tempted to commit suicide, Chad Varah frequently referred to his early-acquired expertise in offering marriage guidance to young couples, and to teaching sex generally to youngsters in his youth clubs. "As a result," he used to say, "I became very knowledgeable and practised", and he even went so far as to claim to have ushered in the "permissive society". In his nineties, he described himself as the "world's oldest sex therapist". He was to a fair degree obsessed by sex (one of his more esoteric writings was a 1976 book called Telephone Masturbators and How to Befriend Them) and it has even been suggested that Varah's initial motive in setting up an emergency telephone service was in order to offer sexual counselling, and that it was from this springboard that the far more broadly based Samaritan movement developed.

During the first year of operation, some 100 callers were seen. Volunteers were recruited on an alarmingly ad hoc basis. There was little structured training but a good deal of glamorous dashing about "seeking souls to save". The earliest "rector and assistants", as Varah's first followers were called, banded together into a Company of Samaritans, holding special services of dedication and admission, and for the first 10 years, only clergy were appointed as local directors. It was small wonder that, with the name "Samaritan" attached as well, the movement was so soon and so strongly identified with religiosity. But today one of the seven principles governing the work of the Samaritans expressly forbids any volunteer to impose their own convictions or to influence callers "in regard to politics, philosophy or religion".

The first branch outside London was founded in Edinburgh in 1959, and others soon followed at Liverpool, Glasgow and Aberdeen. By 1961 there were Samaritan centres in Belfast, Bournemouth, Bradford, Hull, Jersey and Portsmouth, and enthusiasm for the Samaritan ideal of "listening acceptance and personal caring" had spread to what was then Salisbury in Rhodesia, to Karachi, Bombay and Hong Kong. In 1963, attempted suicide ceased to be a crime, and that year 21 founding branches were incorporated into a company called the Samaritans, to be run in future by a Council of Management. In 1974 a further milestone was reached when delegates from all over the world met at St Stephen Walbrook to establish Befrienders International, the Samaritans Worldwide, of which Chad Varah became the president.

The numbers of Samaritans recruited since 1953 must run into hundreds of thousands; around 17,000 volunteers are on the rota of the United Kingdom branches at any time, with thousands of new recruits needed each year just to keep pace with the drop-out rate. No one knows how many suicides have been prevented, but some five million contacts with the Samaritans (by telephone, email or face-to-face) are dealt with in this country every year alone.

The establishment of the Samaritans was a major achievement by any standards, but as Chad Varah grew older and his movement grew larger his inevitable loss of personal control caused him to withdraw into a severe paranoia never far below the surface at the best of times, and in his later years the cause of much grief to those who had admired his basic concepts. He seemed quite incapable of resting on his laurels, and the wildest letters and accusations flew about. He attended his last annual conference in 1986, and resigned from all official connections later that year. In the Samaritans' 50th anniversary year, Varah, claiming that the organisation had strayed from its original aims, wrote to the Charity Commission asking that its charitable status be removed, but later a rapprochement was achieved.

Varah was made an Honorary Prebendary of St Paul's Cathedral in 1975 (and a Senior Prebendary in 1997) and an Honorary Fellow of Keble College in 1981. He was appointed OBE in 1969, advanced to CBE in 1995 and was awarded the Albert Schweitzer Gold Medal in 1972. In 2000, he was made a Companion of Honour.

Varah believed in reincarnation and his autobiography, published in 1992, was titled Before I Die Again.